Photographic device and appurtenance for reproduction purposes



Nov. 6, 1945. a DRUCKER 2,388,394

PHOTOGRAPHIC DEVICES AND A-PPURTENANCES FOR REPRODUCTION PURPOSESOriginal Filed Sept. 18, 1941 I N V EN TOR. Samuel Dracker Patented Nov.6, 1945 PHOTOGRAPHIC DEVICE AND APPURTE- NANCE FOR REPRODUCTION PURPOSESSamuel Drucker, Chicago, 111., assignor to Burke & James, Inc., Chicago,Ill., a corporation of Illinois Continuation of application Serial No.411,340, September 18, 1941. This application May 17, 1944, Serial No.535,945

4 Claims.

This application is a continuation of original application, Serial No.411,340, filed September 18, 1941.

This invention relates to improvements in photographic devices andappurtenances, and more particularly to photographic devices andappurtenances to be used for reproduction purposes.

It is well known that in carrying out certain processes in photography,the graphic arts, and certain highly specialized fields dealing withphoto-sensitive materials, the light used must be of specific wavelength, whereas light of other wave lengths must be excluded.

For some purposes, actinic light, that is, light which is apt to cause achemical change in the particular photo-sensitive material used, and ofwhich white light is an example, must not be present in the processroom. The light which has no eflect on the material being worked upon isknown as non-actinic light. sensitized photographic materials may besensitive to different colors, depending upon the specific purpose forwhich they are intended. Ordinary photo-sensi tive material is notintended to photograph red objects in proper color relation, and such amaterial is not aifected by red light, which means that with respect tosuch a material red light is nonactinic, whereas white light would beactinic.

Furthermore, it is Well known that the color reflected by materialsdepends upon the nature of the material. For example, red paint reflectsred light, but absorbs most of the other colors, if not all of them.Pure blue paint reflects pure blue light, but absorbs all of the othercolors, and so on. White objects reflect all the colors to which theyare subjected in equal amounts; that is to say, if a white object issubjected to, e. g., red light, it will reflect red, and if it issubjected to blue light, it will reflect blue, and so on. In otherwords, a white object is not selective in its reflection, but reflectsall colors to which it becomes subjected indiscriminately.

It is an object of this invention to provide in or for a photographicreproducing device, a member adapted to serve as a support or backgroundfor a photo-sensitive material, which member is of such a nature as toform a selective reflecting means, reflecting at least a everysubstantial part of, if not all, the light rays of a specified wavelength, but, at the same time, rays of this specifled wave length only.

More specifically, it is an object of the invention to provide in or fora photographic reproducing device, a member adapted to serve as abackground or support for a photo-sensitive material, which member is ofsuch a nature as to reflect at least a very substantial part of all thenon-actinic rays of a certain color reaching the member, while absorbingthe actinic light rays.

Certain photographic reproducing devices are intended to carry out onephase of the reproduction process under non-actinic light, and anotherphase under actinic light, e. g., white light. It is an object of thisinvention to provide a member adapted to serve as a background orsupport for a photo-sensitive material, which member will serve twodifferent purposes during the two phases mentioned, namely, reflectingduring the phase in which only non-actinic light is directed toward themember, sufficient of this non-actinic light to permit observation andadjustment of a p j tion of the image to be printed, and preventing,during the second phase, when the photO-sensitive material is placed onthe supporting member and light containing actinic as well asnon-actinic rays is passed onto and through the sensitive material, allbut certain non-actinic rays of a specified color from being reflectedback.

The invention has specific advantages when applied to photographicenlargers, and an example of this particular application of theinvention will be described more in detail, reference being had to theaccompanying drawing, in which:

Fig. 1 is a perspective view of an enlarger equipped with a selectivelyreflecting member, in accordance with the principles of this invention,the enlarger being otherwise of conventional construction; and

Fig. 2 shows an easel placed upon the baseboard of the enlarger shown inFig. 1.

In the drawing, the numeral [0 designates a light source adapted toproduce light which contains actinic, as well as non-actinic rays, suchas white light.

The numeral ll designates a lamp housing, l2 the usual negative carrier,I3 a projection lens, and M a colored transparent plate of shieldusually called the safe-light filter. The filter I4 is so mounted thatit may be moved into and out of the path of the light emitted by thelamp [0, and passing through the lens [3. The filter I4 is of somenon-actinic color, generally of red color, such as ruby.

Below the above-referred-to parts, which together form the so-calledenlarger head, there is arranged a baseboard IS. The sensitized paperupon which a print is to be made, may be placed either directly upon theopaque baseboard 15, or a special easel l6 may be employed, as shown inFig. 2, and is well known in the art.

-filter M in the path of the rays emitted by the lamp ID. If the filterM is of ruby color, the rays of light directed from the enlarger headonto the baseboard I will be ruby rays. Guided by the projected image onthe baseboard, various adjustments of the enlarger are usually made, in

order to adjust the projected image to a desired size, to obtain aproperly focused image, to determine which kind of projecting lens isthe most appropriate for a certain negative, how the easel, where suchis used, is to be adjusted, etc.

In order to make the image projected through the filter in non-actiniccolor clearly visible on the baseboard l5, it has heretofore been thepractice to use a baseboard having a white surface. Such a white surfacewill reflect the non-actinic light projected thereon through the coloredsafeligh t filter, and, therefore, there will be visible to the observeran image on the baseboard which is of the color of the filter, in theexample mentioned of ruby color. While such a white enlarger baseboardaffords good visibility of the image projected thereupon withnon-actinic light rays, it has been found that draw-backs are connectedwith the use of such a white baseboard during that phase of the processin which, for making the actual exposure of the sensitized paper placedupon the baseboard, this paper is subjected to the action of white lightprojected through the lens [3 without the use of the safe-light filter.In this operation, the rays of white light pass through the paper, andif a white baseboard is used as a support for the sensitized paper,these actinic rays will be reflected back through the paper. This backreflection of white light will cause cloudy or hazy effect, to beimparted to the reproduction.

The present invention avoids this draw-back by using a baseboard l5which is not of white color, but of non-actinic color, in particular, ofthe same non-actinic color as the filter 14. If the filter I4 is of rubycolor, then at least those surfaces of the baseboard [5 which face thelens l3, and, therefore, are exposed to light are also colored ruby. Itwill be found that a ruby surface under ruby light, willappear the sameto an observer as a white surface under ruby light, and that an imageprojected by ruby light will present itself to the observer inpractically the same manner, whether the baseboard upon which the imageis projected is white or ruby. Under white light, however, the redbaseboard will act difierently from a white one. Whereas a whitebaseboard will reflect, without any selection, all

I the actinic and non-actinic rays reaching the baseboard after havingpassed through the paper on that baseboard; the opaque red baseboard,when reached by such actinic and non-actinic rays, will reflectselectively only those nonactinic rays which are of red color, whilearresting by absorption all the actinic rays, as well as thosenon-actinic rays which difier in wave length from the wave length ofred. Therefore, any rays of light which are reflected back through thepaper by the baseboard will be non-actinic, and the objection whichexisted with regard to white baseboards will be overcome.

If an easel it is used for holding the enlarging filter l4 and thebaseboard The gaugelines' or gauge figures I! which are usually employedon the easel, should also be of a non-actinic color, e. g., a bold red.

It will be understood that the colored baseboard 5 or othersurfacecontemplated to serve as a selective reflecting means within thepurview of the present invention must not be transparent, but should besufficiently opaque to reflect at least a major part of the selectednon-actinic rays reaching the baseboard. A transparent plate would notbe suitable, for two reasons: 7 (1) A transparent plate would reflect solittle of the colored light that a very faint image only, if any imageat all, would be visible to an observer. It is well known that anordinary transparent glass plate, for instance, does not reflect morethan approximately 8% of the oncoming light, 4% at the front surface andapproximately the same amount at the rear surface of the transparentplate.

(2) As just mentioned, a transparent plate produces a double reflectioneffect, one on the front surface and another on the rear surface of theplate. Therefore, particularly if the two surfaces of the transparentplate are not finished to a very exact parallelism, the observer may seeon the baseboard a doubled image or an image having blurred contours,even though the enlarger may have been adjusted to the position in whichoptimum sharpness of the print would be obtainable. 7

While I have shown, in thedrawing, a certain type of enlarger, it is tobe understood that this particular type of enlarger has been shown byway of example only, and that the invention is applicable not only toenlargers of other types, but also to photographic reproducing devicesother than enlargers.

What I claim is: v

vice having asource of light emitting actinic and non-actinic rays,optical focussing means, and a light filter of a non-actinic colordisplaceable from a position in the path of the rays produced by saidsource of light to a position outside of saidpath of said rays so as tointercept, when placed in the path of said rays, all.rays emitted bysaid sourceof light with the exception of the non-actinic rayscorresponding in color to the color of said filter, an opaque memberadapted to sustaina sensitized element at a distance from said focussingmeans andsaid light filter, at least those surfaces of said opaquememher which, whensaid member is-i'n use, are exposed to light from saidsource. of light being colored in the same non-actinic color as saidfilter. a a

2. In or for a photographic enlarger having a projection'systemincluding-a projection lens, a source of light emitting actinicandnon-actinic rays behind said projection lens,.and alight 'filter of anon-actinic color displaiceable froma position in the path of theraysproduced by I said source of light to a position outside of saidpath so as to intercept, when placed in the path of said rays, all raysemitted by said source of light with the exception of the non-actinicrays corresponding in color to the color of said filter,

tized element facing said projection lens and said light filter at adistanceso that an imagemay be projected through said light filter ontosaid opaque member or, when said sensitized -element is placed on saidmember, onto said element,

1. In or for a photographic reproducing dean opaque member adapted tosustain a sensi-- at least those surfaces of said opaque member whichduring use face said lens being colored in the same non-actinic color assaid filter, so as to reflect of the rays passing through said filterwhen an image is projected through said filter onto said opaque memberat least a major part, creating thereby a reflected image in the colorof said filter which is readily observable for adjustment and focussingpurposes, while acting as a means for arresting by absorption anyactinic rays reaching said member when said filter is removed from thepath of the rays produced by said projection system.

3. In a photographic enlar er having a projection system including aprojection lens, a source of light emitting actinic and non-actinic raysbehind said projection lens and a light filter of a non-actinic colordisplaceable from a position in the path of the rays produced by saidsource of light to a position outside of said path so as to intercept,when placed in the path of said rays, all the rays emitted by saidsource of light with the exception of the non-actinic rays correspondingin color to the color of said filter, an opaque base-board facing saidprojection lens and said light filter at a distance so that an image maybe projected through said light filter onto said base-board, saidbase-board having at least those surfaces facing said lens and saidlight filter colored in the same non-actinic color as said filter so asto reflect of the rays passing through said filter when an image isprojected through said filter onto said base-board at least a majorpart, creating thereby a reflected image in the color of said filterwhich is readily observable for adjustment and focussing purposes, whileacting as a means for arresting by absorption any actinic rays reachingsaid baseboard when said filter is removed from the path of the raysproduced by said projection system.

4. For use with a photographic enlarger having a projection systemincluding a projection lens, a source of light emitting actinic andnonactinic rays behind said projection lens and a light filter of anon-actinic color displaceable from a position in the path of the raysproduced by said source of light in which it intercepts all the raysemitted by said source of light except the non-actinic rayscorresponding in color to the color of said filter to a position outsideof said path, an easel having the easel board facing said lens and saidlight filter when that asel is placed for use with the enlarger coloredin the same nonactinic color as said filter so as to reflect of the rayspassing through said filter when an image is projected through saidfilter onto said easel at least a major part, creating thereby areflected image in the color of said filter which is readily observablefor adjustment and iooussing purposes, while acting as a means forarresting by absorption any actinic rays reaching said member when saidfilter is removed from the path of the rays produced by said projectionsystem.

SAMUEL DRUCKER.

